


Manners

by orphan_account



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell, Ecto-Genitalia, Ecto-Tongue, M/M, NSFW, PWP, Tumblr request
Language: English
Status: Completed
Published: 2016-05-31
Updated: 2016-05-31
Packaged: 2018-07-11 11:28:53
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,670
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7047814
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: <blockquote class="userstuff">
              <p>(UF fontcest) You are much more likely to get what you want, if you ask nicely.</p>
            </blockquote>





	Manners

**Author's Note:**

> Requested by an anon on tumblr.  
> https://www.tumblr.com/blog/skelejizz

“Do you have any idea how fucking dangerous that was!?” Sans slammed him against the wall harshly, and Papyrus staggered, momentarily taken by surprise at his brother's sudden anger. “You could have gotten yourself killed!”

“Keh! It's nothing.” He snarled back, bringing a hand up defensively, in an effort to push the smaller skeleton of him. But Sans griped his wrist, surprisingly tight, and pulled him closer instead.

“You call this nothing?!” He wrenched Papyrus' arm again, for added effect.  
The movement made the fresh cut in his clavicle sting painful, and the tall skeleton flinched automatically.

He opened his mouth to reply, to bite back some smarting comment, but snapped his jaw shut when he saw the look on his brother's face. Two burning pinpricks of red light in deep hollow sockets.

It sent a shudder down his spine, and not an entirely unpleasant one...

“I'm fine...” He scoffed, averting his gaze. “That blow would have killed you.”

“Never-fucking-do-that-again!” Sans' voice was clipped, each word accompanied by a tug on Papyrus' arm that forced him to bend down awkwardly, leveling out their height difference.

“Yes, sir.” The tall skeleton mocked. “Next time I'll be sure to let you die, then.”

But the older skeleton ignored the second part of his statement, a mischievous smile creeping over his face at the title, golden tooth glinting dangerously.

Sans bent forward, and for a second Papyrus was caught between pushing him off or doing nothing.

He gasped instead as Sans trails a wet tongue along the cut, the stinging pain edged by sudden pleasure.

It ran all the way along his clavicle, sweeping almost languidly over the lowest vertebrae. When Sans pulled back again, there were little specks of gray dust on his tongue.

“Who would have thought you taste so good, Boss” He ran the appendage along his teeth slowly, before leaning in for another taste.

Papyrus braced his hands against his brother's shoulders, not pushing away, fingers clenching in the dull colored fur along the other's hoodie tightly.

“Sans, don't be disgust-AAH-” The reprimand trailed off into an undignified groan when sharp fangs sink down into the bone.

“I liked it better when you were still calling me sir.” The small skeleton smirked, and Papyrus could feel the corner of his own mouth pulling up in response.

“In your fucking dreams.” He growled, pushing his leg up to grind against Sans' pelvis, telltale red glow visible even through the dark fabric.

Sans grunted in satisfaction, running his tongue along the sensitive crack once more, teasing between the clavicle and scapula.

Papyrus threw his head back, thumping it against the wall harshly, in a vain effort to avoid making any noises, yet couldn't quite contain the small groan forcing its way out of his throat when he felt his brother's hand grasp his spine.

Sans was rutting into him almost desperately now, dry humping against his leg with vigor, while sharp phalanges prod between his vertebrae.

Papyrus felt Sans still, now fully formed erection pressed firmly against his thigh, as the older brother pulls back with a smug grin.

“Get on your knees.” He commanded, voice nearly guttural in anticipation.

The dominant tone was almost enough to make the tall skeleton's knees buckle right then and there, but he wouldn't be the great Papyrus if he went down without a fight.

Grinding his leg forward once more, enjoying the way Sans clenched his teeth at the friction, he let out a small laugh. “You didn't say the magic word.”

“Get on your knees, now.” There was a harsh pull on his scarf, the hand still resting on his spine sliding down roughly, and Papyrus was pretty sure he wouldn't be able to keep standing even if he wanted too.

His knees hit the ground with an audible click, and before he could blink there was a hard, red member mere inches from his face.

“Now be a good little brother and suck my cock, won't you?” Sans nearly purred, face now slightly flushed as well.

For a split second, Papyrus considered refusing the order, but it seemed his brother was not in the mood for their usual games.

One hand was already braced against the back of the younger skeleton's skull, other loosely grasping the bottom of the straining magical appendage.

Papyrus complied, bending forward and allowing his brother to slide inside, summoned tongue rubbing the underside of that considerable girth.

His hands loosely grabbed on to Sans' femurs, as his brother started thrusting in a quick rhythm.

Papyrus wasn't often on this side of procedures, his technique probably left something to be desired, sharp teeth brushing against the tip every time Sans pulled back.

But judging by the pleasurable hisses his brother made, this wasn't an entirely bad thing either.

After a few minutes, Papyrus felt himself fidgeting slightly, own body responding to Sans' magic building in the air, sending a tingling sensation down the back of his spine, gathering near the front of his pelvis.

Sans noticed his agitation, pulling out with a small smirk, the hand that had been bracing against the back of his skull coming to rest against his cheek instead.

“That's a good look on you, Boss.” he hummed, eyes half-lidded as he regarded his brother's debauched state.

And what a state he must look. He felt flushed, face redder than it should be, and his tongue tasted vaguely of pre-cum and spit.

With a sharp tug at those femurs, Papyrus made his brother fall down on top of him with an impatient growl. “Less talking, more fucking.”

“You're really no good at this, are you?” Sans couldn't quite suppress the humor in his voice as he undid his brother's belt, awkwardly trying to pull the fabric out of the way in their half-seated position.

His own shorts had slid down to his knees, but besides this they were both still fully clothed. It made the whole act seem more hasty somehow, more vulgar. Sans loved it.

“Stop complaining and hurry up...” Papyrus hissed in response, slight desperation seeping into his voice. His magic had gathered to form a dripping entrance at the bottom of his pelvis, and the way Sans was rubbing his heated cock against it was really testing his fragile patience.

“Jeez, Boss, you're acting like a whiny little bitch.” Sans droned, really taking advantage of his temporary power. “So eager for the bone.”

“SA-Ngh” The angry response Papyrus tried to growl out turned into a high-pitched whine as the small skeleton slowly pushed inside him, magic rushing to accommodate the intrusion.

Sans didn't pause either. Their pelvises barely brushed together, or the older brother was pulling out again, agonizingly slow, enjoying the clench of his brother's magic around his heated member.

Hands bracing against the floor, Papyrus nearly whined as Sans kept the pace slow and unsatisfying. There was a pleasurable burning filling his entire bottom half, but he needed more to get even close to finishing.

The sounds were downright lewd. A slick sliding noise, and an almost indiscernible click each time Sans buried deep inside him. Uneven, pleasured groans filled the room.

“S-Sans.” His teeth were clenching hard enough to hurt, eye sockets screwed shut. “Just...fucking..move....”

All motion stopped, and it was all Papyrus could do not to start sobbing right then and there. When he opened his eyes, Sans was looking down at him with a positively sadistic expression.

“You didn't say the magic word.”

Had there been any strength left in his arms, Papyrus would have dusted him. As it was, he only gritted his teeth harder. “Just fucking move, now!”

There was one, quick thrust, and the tall skeleton gasped as the blunt head of his brother's cock brushed against his coccyx.

But then Sans stilled once more. “Wrong. Try again?”

Papyrus averted his head, staring at anything but his brother's pleased expression. “Just fucking move... please.”

Sans' pleased little smirk was almost too much to bear. “Since you're asking so nicely.”

The movements picked up again, this time not languidly in nature, but more like animalistic rutting.

Sans fucked Papyrus hard and fast, and the younger sibling's moans gradually rose in pitch and volume as his magic rushed through him, a building pressure coursing through his bones and gathering in his soul at an unbearable level.

“Agh..F-fuck... Sans...Please-” The position made it impossible for him to grind his hips down in return, leaving him completely exposed and at his brother's mercy.

Sans merely grunted in response, hands grasping hard on femurs, as he pushed inside his little brother over and over again, feeling his own orgasm build hard and fast.

Papyrus' pleas had turned into inarticulate cries, the world narrowed down to the pounding inside of him and the feeling of a burning heat in his chest, when the steadily burning pleasure simply snapped.

It felt like a wave of ecstasy just washed over him, a shudder that surged through his body and up his spine and the feeling of something hot and wet against the inside of his pelvis.

For a few seconds, everything went blank.

When it settled, Sans was still half on top of him , apparently trying to snuggle into his collarbone.

“Get off.” Papyrus grunted, pushing against his brother's shoulder, becoming acutely aware of how uncomfortably the wall was digging into his back.

With another sly grin, Sans rolled off him, sprawling on the floor instead, shorts still tangled around his knees. “We should do that more often.”

Papyrus tried to throw his brother a long suffering look as he got up, but the small skeleton had his eyes closed, seemingly only moments away from falling asleep right then and there.

Instead, he deftly straightened himself out and moved to leave, tapping one heeled boot against Sans' skull in passing, making him open his eyes and look up at him.

“Maybe if you ask very nicely.” He said, and ignored the amused snort he got in response.


End file.
